Structural variation and piezoelectric properties of 0.95(Na0.5K0.5)NbO3–0.05BaTiO3 ceramics

• Published in: Sensors and actuators. A. Physical. Vol. 136; no. 1; pp. 255 - 260
• Main Authors: Ahn, Cheol-Woo, Park, Hwi-Yeol, Nahm, Sahn, Uchino, Kenji, Lee, Hyeung-Gyu, Lee, Hwack-Joo
• Format: Journal Article
• Language: English
• Published: 01-05-2007
• ISSN: 0924-4247
• DOI: 10.1016/j.sna.2006.10.036

A dense microstructure was developed for the 0.95(Na0.5K0.5)NbO3-0.05BaTiO3 (0.95NKN-0.05BT) ceramics sintered at above 1050 deg C. Grain growth was observed in the specimens sintered at 1050-1060 deg C while a liquid phase was found in the specimens sintered at above 1050 deg C, which explained the increased sinterability and grain size. KTiNbO5 and Ba6Ti2Nb8O30 second phases were also observed for the specimens sintered at above 1060 deg C. Evaporation of Na2O was responsible for the formation of the liquid phase and the KTiNbO5 and Ba6Ti2Nb8O30 second phases. Muffling with 0.95NKN-0.05BT powders during the sintering improved the piezoelectric properties, possibly due to the increased poling efficiency resulting from the reduced Na2O evaporation.